Wing for toy airplanes, particularly helicopters

ABSTRACT

A toy airplane wing, particularly a rotary wing for toy helicopters, comprising an upper and a lower profiled semimonocoque shell members of plastic material joined together to form the wing the profiling being such that only a partly hollow body is formed while the greater part of the wing area consists of flat superposed thin plastic material.

Unite States Seefluth atent 1 Mar. 27, 1973 1 WING FOR TOY A 1" PARTICULARLY LICOPTERS [76] Inventor: Uwe C. Seefluth, 2409 Klingberg,

Seestrasse, Klingberg, Germany 22 Filed: Feb. 8, 1971 21. Appl.No.: 113,496

1,632,179 6/1927. Foerster ..46/82 10/1952 Main ..46/74 R 3/1933 Girdwood ..46/74 R Primary ExaminerLouis G. Mancene Assistant Examiner-J. O. Lever AttorneyPolster & Polster ABSTRACT A toy airplane wing, particularly a rotary wing for toy helicopters, comprising an upper and a lower profiled semimonocoque shell members of plastic material joined together to form the wing the profiling being such that only a partly hollow body is formed while the greater part of the wing area consists of flat superposed thin plastic material.

15 Claims, 11 Drawing Figures WING FOR TOY AIRPLANES, PARTICULARLY HELICOPTERS FIELD OF INVENTION Toy airplane wings of the type hereinafter disclosed are preferably used in the toy industry, butmay as well be used for model airplanes.

It is a requirement that such wings not only be sufiiciently strong and stifl but simultaneously it must be assured that the weight of such wing must be kept as low as possible, and that the resistance against the direction of air flow is but little.

BACKGROUND OF INVENTION In manufacturing wings for toy airplanes, and particularly so for model airplane it is a known practice to provide two pre-shaped foils of plastic material and combine the two foil members in a suitable manner. In the known constructions the stifiness of the wings in longitudinal direction was achieved in such a manner that either longitudinally and transversely extending girders were provided in the cavity defined by the profiled foil members of the wing, or that this cavity was filled with foamed material. According to another known construction the semimonocoque shell members of the wing were made of rather thick profiled material so that the thickness of the material provided sufficient stiffness of the wing. In all these prior know constructions the wing either became relatively heavy, or had to be provided with longitudinal and transverse girders, in order to reduce the weight.

Therefore, the problem of this invention is to provid a wing for toy airplanes which, without using additional reenforcing means, is sufficiently stiff, and is of extreme low weight.

SUMMARY OF THE INVENTION In a toy airplane wing, particularly a rotary type wing for toy helicopters formed by a pair of profiled semimonocoque shell members of plastic material, the above mentioned problem of the invention is solved in that the respective wing is formed as a hollow body profiled partly only, while a great part of the wing area consists of flat superposed thin plastic material. The wing construed in accordance with the invention may be made of relatively thin plastic material foil and yet, due to its novel construction, is of extreme light weight, and is sufficiently stiff without providing additional reenforcing means.

Preferably the front portion of the wing facing the direction of air flow is profiled, while the rear portion consists of flat superposed thin plastic material defining no cavities.

According to the invention the assembly of the two shell members is greatly facilitated by providing a narrow flat flange extending along the extreme front portion of the wing, serving to combine the two shell members, as by welding adhering, or the like.

The hollow profiled portion of the wing extends in longitudinal direction of the wing and terminates in spaced relation to the tip of the wing. In this the width of the profiled portion forming the cavity may increase toward the tip of the ring.

One embodiment of the invention provides that only the upper one of the pair of shell members is profiled to form the cavity, while the lower shell member is flat, and, according to another aspect, may be bent slightly downwardly. In this the rear end of the flat portion of the wing may include an angle with its apex coinciding with the longitudinal rear chord of the cavity. Preferably the flat portion of the wing is formed to the greater part by only one of the pair of shell members.

In order to decrease the resistance against the air flow the profiled portion of the wing should, according to the invention, have the shape of an airfoil, wherein the upper and the lower shell member may be profiled equally.

It has been found that a good performance is achieved when the profiled portion amounts to less than half of the width of the wing.

According to the invention in the so far described wing its profiled portion may be of round or oval cross sectional shape at the root of the wing, and may extend therefrom convergingly in longitudinal direction of the wing, merging in spaced relation to the tip of the wing into the superposed portions of the shell members.

Another advantageous feature of the invention resides in that connecting means reenforcing the wing are joined to the root of the wing. These connecting means may be in form of a tube of plastic material joined to the root of the wing in any suitable manner, as by welding, or adhering, serving atthe same time to connect the wing either to a rotor hub, or to a fuselage of an airplane.

' In accordance with the invention a plurality of wings joined by a hub may be formed by a lower integral shell member and by an upper integral shell member forming a rotary wing for a toy helicopter.

Several exemplified embodiments in accordance with the invention shall now be described in detail in connection with the annexed drawings.

. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective cross sectional view of the wing according to the invention;

FIG. 1a is a perspective top view of the wing according to one embodiment;

FIG. 1b is a side view of the wing shown in FIG. 1a;

FIG. 1c is a perspective top view of the wing according to a somewhat altered embodiment;

FIG. 2 a perspective cross sectional view of the wing having an upper shell member differing from the lower shell member;

FIG. 3 and 3a are perspective cross sectional views of a wing provided with planar areas extending angularly with respect to the chord of the profile;

FIG. 4 and 4a are perspective cross sectional views of a wing in which the lower member is not profiled;

FIG. 5 is a top view of a rotary wing including three blades integrally combined with a rotor hub; and

FIG. 5a is a side view of the rotary wing shown in FIG. 5.

In FIG. 1 the wing according to the invention is shown in a perspective cross sectional view. The profiled hollow body 1 is formed in such a manner that the upper shell member is profiled over part of the width of the wing. This may be achieved by pre-shaping a foil of plastic material according to the well known cupping.

The rear portion 2 of the wing is formed by two flat superposed parts of material. At the front edge of the wing there is provided a flat narrow flange serving to combine the semimonocoque shell members, as by welding, or adhering.

FIG. 1a shows the same wing in a perspective top view, illustrating that only the forward part 1 of the width of the wing has been profiled, while the rearward part is flat. In this the profiled part 1 merges into the flat part in spaced relation to the tip 4 of the wing, whereby the free end zone 4 of the wing is formed by flat not profiled material. In order to reenforce the root of the wing, there is provided a reenforcing member, which may be in form of a tube, or a pin, preferably made of plastic material. With the aid of this tube or pin, which may be adhered to the root of the wing, the wing may advantageously be secured to a hub, or to an airplane fuselage.

FIG. lb shows the same wing sectioned longitudinally.

FIG. differs from the wing shown in FIGS. la and 1b in that the profiled part of the wing increases in width toward the tip of the wing, at the same time converging in height and terminating in a flat shape, with the advantageous result that the longitudinal stiifness of the wing is increased and that the same time the resistance against the flow direction of the air is reduced.

FIG. 2 shows a wing according to the invention having upper and lower semimonocoque shell members of differing width. In this case the flat rear wing zone 6 is substantially formed by the lower shell member, while the upper shell member is shortened forming an edge 8, whereby a reduction in weight is achieved.

In FIGS. 3 and 3a the flat portions of the wing are arranged at an angle relative to the chord 10 of the profile. In this case a more favorable approach flow of air against the wing may be obtained under certain conditions whereby the lift may be increased, and at the same time the turbulence at the rear edge of the flat portion of the wing is reduced.

In the embodiment shown in FIGS. 4 and 4a only the upper member of the assembled wing is partly profiled. The lower member 1 1, as shown in FIG. 4, is completely fiat, while, as shown in FIG. 4a, it is is slightly uniformly curved over its entire width. By means of this construction of the wing not only the air resistance of the wing is reduced, but also the manufacturing costs are reduced and in FIG. 4a the curvature of the lower member will cause an improved lift. In FIGS. 5 and 5a a plurality of wings in accordance with the invention are combined as a unit to form a rotary wing. In both cases the entire rotary wing consists of a lower and an upper semimonocoque shell member, wherein the leading portions of the wings or blades and the rotor hub are profiled, while more than half of the width of the trailing portions of the wings and the adhering edges are flat.

In FIG. 5a the rotary wing blades are slightly inclined relative to their plane of rotation whereby a good stabilization of the rotary wing is achieved during flight consitions. Here also, the rotary wing consists of an integral upper member and an integral lower member.

The advantages achieved by the invention are particularly to be seen in the fact that the weight of the wings for light toy airplanes can be reduced substan tially, and that simultaneously the strength and stiffness in longitudinal direction of the wing is assured by an optimum width of the profiling and reduction thereof to a part of the total width of the wing. At the same time it is achieved that the profiled hollow parts of the wing do not require additional reenforcing means, such as foamed material, or longitudinal and transverse girders. Another advantage is to be seen in the fact that the wing can be manufactured in a simple manner by a deep drawing method and welding, or adhering.

What I claim:

1. A toy airplane wing, formed by a pair of profiled semimonocoque shell members of plastic material, said wing being formed as a hollow body having a profiled front portion facing the direction of air flow and defining a cavity, while the rear and tip portions of said wing consist of fiat superposed thin plastic material defining no cavities, wherein the extreme front of said wing adjacent said cavity comprises a narrow fiat flange serving to combine said semimonocoque shells in a suitable manner as by welding, adhering, or the like, said hollow profiled portion of said wing extending in longitudinal direction through a major portion of the length of said wing and terminating in spaced relation to the tip of said wing, said hollow profiled portion of said wing having a round or oval cross-sectional shape at the root of said wing and extending therefrom convergingly in longitudinal direction of said wing merging in spaced relation to the tip of said wing into said flat superposed portion of said semimonocoque shells.

2. A toy airplane wing' as claimed in claim 1, wherein connecting means reenforcing said wing are joined to the root of said wing.

3. A toy airplane wing as claimed in claim 2, wherein said connecting means is a tube of plastic material joined to the root of said wing in any suitable manner as by welding, or adhering and serving to connect said wing to a rotor hub.

4. A toy airplane wing as claimed in claim 3, wherein said connecting means is inserted into an opening formed in the root of said wing and serving to connect said wing to a fuselage of an airplane.

5. 'A rotary wing for toy helicopters, wherein the wing is made up of a plurality of blades formed by a pair of profiled semimonocoque shell members of plastic material, the invention residing in that the blades are formed as a unitary hollow body having a profiled front portion facing the direction of air flow and defining a cavity, while the rear portion of said blades consists of flat superposed thin plastic material defining no cavities, wherein the extreme front of said blades adjacent said cavity comprises a narrow flat flange serving to combine said semimonocoque shells in a suitable manner as by welding, adhering, or the like, said hollow profiled portion of said blades extending in longitudinal direction of said blades and terminating in spaced relation to the tip of said blades, said hollow profiled portion of said blades having a round or oval cross-sectional shape at the root of said blades and extending therefrom convergingly in longitudinal direction of said blades merging in spaced relation to the tip of said blades into said flat superposed portions of said semimonocoque shells, wherein said plurality of blades are joined by a hub formed by a lower integral shell member and by an upper integral shell member forming said rotary wing for a toy helicopter.

6. A rotary type wing for toy helicopters comprising a plurality of blades of plastic material, each of said blades having a leading edge and a trailing edge, each of said blades being unitary, long and relatively narrow, and hollow and profiled along an area closer through a major portion of its length to the leading edge than to the trailing edge and through a major portion of the length of the blade, the remainder of. said blade being solid, the width of said hollow profiled portion increasing toward the tip of the blade.

7. The wing of claim 6 wherein each blade is formed by a pair of semimonocoque shell members secured to one another.

8. The wing of claim 7 wherein the area of each blade between the leading edge and the hollow profiled area is flat and made up of superposed, joined flat areas of the two semimonocoque shell members.

9. The wing of claim 7 wherein the hollow area of each blade terminates in spaced relation to the outer tip of said blade.

10. The wing of claim 7 wherein only the upper one of the said pair of.shell,- members is profiled, while the lower shell member is planar.

11. The wing of claim 6 "wherein the blade area between the hollow, profiled area and the trailing edge is bent at an angle, the apex of which coincides with a longitudinal chord of the profiled hollow area.

12. The wing of claim'7 wherein the solid portion of the blade is formed to the greater part by only one of said pair of semimonocoque shells.

13. The wing of claim 7 wherein the upper and lower shell members are mirror images of one another.'

14. The wing of claim 6 wherein the width of the ho]- low, profiled area amounts to less than half of the width of the blade.

15. The wing of claim 6 wherein the semimonocoque shell members are secured by welding. 

1. A toy airplane wing, formed by a pair of profiled semimonocoque shell members of plastic material, said wing being formed as a hollow body having a profiled front portion facing the direction of air flow and defining a cavity, while the rear and tip portions of said wing consist of flat superposed thin plastic material defining no cavities, wherein the extreme front of said wing adjacent said cavity comprises a narrow flat flange serving to combine said semimonocoque shells in a suitable manner as by welding, adhering, or the like, said hollow profiled portion of said wing extending in longitudinal direction through a major portion of the length of said wing and terminating in spaced relation to the tip of said wing, said hollow profiled portion of said wing having a round or oval cross-sectional shape at the root of said wing and extending therefrom convergingly in longitudinal direction of said wing merging in spaced relation to the tip of said wing into said flat superposed portion of said semimonocoque shells.
 2. A toy airplane wing as claimed in claim 1, wherein connecting means reenfOrcing said wing are joined to the root of said wing.
 3. A toy airplane wing as claimed in claim 2, wherein said connecting means is a tube of plastic material joined to the root of said wing in any suitable manner as by welding, or adhering and serving to connect said wing to a rotor hub.
 4. A toy airplane wing as claimed in claim 3, wherein said connecting means is inserted into an opening formed in the root of said wing and serving to connect said wing to a fuselage of an airplane.
 5. A rotary wing for toy helicopters, wherein the wing is made up of a plurality of blades formed by a pair of profiled semimonocoque shell members of plastic material, the invention residing in that the blades are formed as a unitary hollow body having a profiled front portion facing the direction of air flow and defining a cavity, while the rear portion of said blades consists of flat superposed thin plastic material defining no cavities, wherein the extreme front of said blades adjacent said cavity comprises a narrow flat flange serving to combine said semimonocoque shells in a suitable manner as by welding, adhering, or the like, said hollow profiled portion of said blades extending in longitudinal direction of said blades and terminating in spaced relation to the tip of said blades, said hollow profiled portion of said blades having a round or oval cross-sectional shape at the root of said blades and extending therefrom convergingly in longitudinal direction of said blades merging in spaced relation to the tip of said blades into said flat superposed portions of said semimonocoque shells, wherein said plurality of blades are joined by a hub formed by a lower integral shell member and by an upper integral shell member forming said rotary wing for a toy helicopter.
 6. A rotary type wing for toy helicopters comprising a plurality of blades of plastic material, each of said blades having a leading edge and a trailing edge, each of said blades being unitary, long and relatively narrow, and hollow and profiled along an area closer through a major portion of its length to the leading edge than to the trailing edge and through a major portion of the length of the blade, the remainder of said blade being solid, the width of said hollow profiled portion increasing toward the tip of the blade.
 7. The wing of claim 6 wherein each blade is formed by a pair of semimonocoque shell members secured to one another.
 8. The wing of claim 7 wherein the area of each blade between the leading edge and the hollow profiled area is flat and made up of superposed, joined flat areas of the two semimonocoque shell members.
 9. The wing of claim 7 wherein the hollow area of each blade terminates in spaced relation to the outer tip of said blade.
 10. The wing of claim 7 wherein only the upper one of the said pair of shell members is profiled, while the lower shell member is planar.
 11. The wing of claim 6 wherein the blade area between the hollow, profiled area and the trailing edge is bent at an angle, the apex of which coincides with a longitudinal chord of the profiled hollow area.
 12. The wing of claim 7 wherein the solid portion of the blade is formed to the greater part by only one of said pair of semimonocoque shells.
 13. The wing of claim 7 wherein the upper and lower shell members are mirror images of one another.
 14. The wing of claim 6 wherein the width of the hollow, profiled area amounts to less than half of the width of the blade.
 15. The wing of claim 6 wherein the semimonocoque shell members are secured by welding. 